Implantable cardiac rhythm management devices typically monitor and process heart signals to provide the heart with needed therapy. One example of such therapy includes delivering a pacing pulse that triggers a resulting heart contraction. Another example includes delivering a defibrillation shock that interrupts an abnormal heart rhythm. Some cardiac rhythm management devices also monitor the patient's breathing (also referred to as the patient's respiration). Such devices typically use breathing to control the delivery of pacing pulses to increase the patient's heart rate when the patient breathes more rapidly, and to slow the patient's heart rate when the patient breathes more slowly.